Method and system for flue gas carbon dioxide capture and utilization

Abstract

The present application relates to the field of flue gas carbon dioxide capture, and particularly relates to a flue gas carbon dioxide capture and utilization method and system, which comprises: an absorption tower, inside which an absorbent is added and flue gas discharged by a factory is introduced, so as to capture carbon dioxide in the flue gas; the absorbent comprises amino acid anion, cation and transition metal complex; the amino acid anion is used to absorb carbon dioxide and reacts with superoxide free radicals to proliferate in a chain; the cation reacts with the product of the chain proliferation to reduce the loss of the chain proliferation; the transition metal complex reacts with the product of the chain proliferation to reduce the loss of the chain proliferation, and also reacts with the amino acid anion to improve the solubility of the absorbent. The present application realizes efficient capture of carbon dioxide in flue gas, stable circulation of the absorbent and recycling of resources.

Description

Technical Field

[0001] This invention relates to the field of flue gas carbon dioxide capture, and more particularly to a method and system for capturing and utilizing flue gas carbon dioxide. Background Technology

[0002] Carbon capture, utilization, and storage (CCUS) technology involves capturing and purifying carbon dioxide emitted during fossil fuel utilization and industrial production, then transporting it for resource utilization or permanent storage, ultimately reducing atmospheric carbon dioxide concentration. It is a key supporting technology for addressing global climate change. Among CCUS technologies, chemical carbon capture technology based on organic amines, with its advantages of high absorption selectivity, high process maturity, and wide applicability to various flue gas conditions, has become the most promising industrial application path for decarbonization of industrial flue gas, especially in coal-fired power plants, steel, and cement industries.

[0003] The core principle of chemical carbon capture technology is to capture and utilize carbon dioxide through a cyclic mechanism of low-temperature absorption and high-temperature desorption by the absorbent: Under low-temperature conditions of 40-60℃, the alkaline absorbent undergoes a selective chemical reaction with carbon dioxide in the flue gas through its functional groups, forming carbamate (R-NCOO⁻) and bicarbonate (HCO₃⁻). - 3) Stable chemically bonded products are obtained, and the process is a thermodynamically spontaneous exothermic reaction. However, at high temperatures of 100-120℃, the chemical bonds of the generated reaction salts break, decomposing and releasing high-purity carbon dioxide, allowing the absorbent to be regenerated and recycled. This desorption process is an endothermic reaction, requiring a large amount of external energy, so the energy consumption level of the absorbent directly determines the overall energy consumption and economic efficiency of the carbon capture process.

[0004] Among them, the first-generation alcohol amine absorbent, represented by monoethanolamine (MEA), is currently the most mature organic amine system. However, due to the extremely strong chemical bond energy between the primary amine group (-NH2) in the monoethanolamine molecule and carbon dioxide (CO2), it is difficult to break the chemical bond during desorption. The energy consumption for carbon dioxide desorption is as high as 3.6 GJ / tCO2 or more, that is, the total energy required to capture, purify and separate 1 ton of pure carbon dioxide is greater than 3.6 gigajoules (GJ). This seriously restricts the economics of the industrial application of the first-generation alcohol amine absorbent.

[0005] To address this issue, second-generation absorbent technology has shifted towards compound organic amine systems. Through synergistic optimization of multiple amine components, it has achieved improvements in absorption rate and capacity while reducing equipment corrosion. This technology has been applied in several major international projects: the Canada Border Dam coal-fired power plant CCS (Carbon Capture and Storage) project uses Cansolv DC103 and DC201 reagents from Shell, Netherlands; the Petrarian Nova coal-fired power plant CCS project in the United States uses Mitsubishi Heavy Industries KS-1 compound amine absorbent from Japan; and compound amine systems such as BASFOASE from BASF, Germany, and HNC-5 from China Huaneng Group have also been demonstrated and put into operation.

[0006] However, even with technological optimization, the regeneration heat consumption of the second-generation compound amine absorbent remains above 2.5 GJ / t CO2. This means that the total energy required to capture, purify, and separate one ton of pure carbon dioxide exceeds 2.5 gigajoules (GJ), resulting in carbon dioxide desorption energy consumption accounting for over 60% of the total energy consumption of the carbon capture process and directly impacting the core component of total operating costs. Therefore, reducing carbon dioxide desorption energy consumption remains a key challenge for achieving breakthroughs in low-energy, low-cost carbon capture technology.

[0007] Besides the critical challenge of high regeneration energy consumption, as carbon capture technology progresses from industrial demonstration to large-scale industrial application, the stability of organic amine absorbent systems has become increasingly prominent in engineering practice, becoming another important bottleneck restricting the large-scale promotion of the technology. Due to the structural characteristics of their functional groups, organic amine molecules are prone to volatilization, escape, and chemical degradation under complex flue gas conditions and during the regeneration process. On the one hand, organic amines and their degradation products are easily emitted with the flue gas, causing not only the loss of effective components of the absorbent and a significant increase in operating costs, but also secondary air pollution and increased environmental protection investment in emission control. On the other hand, impurities in the flue gas undergo complex physicochemical reactions with organic amines, and volatile organic amines and gaseous pollutants are easily mixed into the carbon dioxide product gas during high-temperature regeneration, posing a severe challenge to the subsequent product gas purification process and affecting the resource utilization efficiency of carbon dioxide.

[0008] Therefore, how to develop a low-escape, high-stability absorbent system to reduce the emission of organic amine pollutants and ensure the long-term stable and environmentally friendly operation of carbon capture technology is a technical problem that needs to be solved. Summary of the Invention

[0009] Therefore, the present invention provides a method and system for capturing and utilizing carbon dioxide in flue gas. Through an absorption tower, a regeneration tower and a multifunctional absorbent system, the efficient capture of carbon dioxide in flue gas, stable circulation of the absorbent and resource recovery and utilization are achieved.

[0010] To achieve the above objectives, the present invention proposes a system for capturing and utilizing carbon dioxide in flue gas, comprising:

[0011] An absorption tower is filled with an absorbent and circulated with flue gas emitted from the factory to capture carbon dioxide from the flue gas.

[0012] The regeneration tower is used to pass in an absorbent that combines with carbon dioxide to recover the absorbent and produce pure carbon dioxide.

[0013] The absorbent comprises amino acid anions, cations, and transition metal complexes;

[0014] The amino acid anions are used to absorb carbon dioxide and react with superoxide radicals to carry out chain proliferation.

[0015] The cation reacts with the products of the chain proliferation to reduce the loss of the chain proliferation.

[0016] The transition metal complex reacts with the products of the chain proliferation to reduce the loss of the chain proliferation, and also reacts with the amino acid anion to improve the solubility of the absorbent.

[0017] Furthermore, the amino acid anion includes any one or more of nonpolar amino acid anions and polar amino acid anions, and the reaction process of the amino acid anion reacting with superoxide radicals to carry out chain proliferation is as follows:

[0018] O2+ e - →⋅O2 − ,

[0019] R-CH(NH2)COO − +⋅O2 − →RC⋅(NH2)COO − +HO2 − ,

[0020] RC⋅(NH2)COO − +O2→RC(OO⋅)(NH2)COO − ,

[0021] RC(OO⋅)(NH2)COO − +R′-CH(NH2)COO − →RC(OOH)(NH2)COO − +R′-C⋅(NH₂)COO − 。

[0022] Furthermore, the nonpolar amino acid anion includes any one or more of α-alanine anion, β-alanine anion, 2-aminoisobutyric acid anion, and proline anion;

[0023] The polar amino acid anions include any one or more of glycine anion, arginine anion, sarcosine anion, taurine anion, glutamic acid anion, lysine anion, asparagine anion, and aspartic acid anion;

[0024] The metal complex includes products formed by coordination of any one or more of chromium, manganese, nickel, copper, zinc, and cobalt with the amino acid anion.

[0025] Furthermore, the cation includes a metal cation, and the metal cation includes Cr. 3+ Ni 2+ Al 3+ Mn 2+ Co 2+ Zn 2+ The reaction process in which any one or more of the metal cations react with the products of chain proliferation to reduce the loss of said chain proliferation is as follows:

[0026] M 2+ +2RNH2→[M(RNH2)2] 2+ ,

[0027] ROOH+M 2+ →ROH+M 3+ +OH−,

[0028] Where M represents Cr 3+ Ni 2+ Al 3+ Mn 2+ Co 2+ Zn 2+ Any one of them.

[0029] Furthermore, the cations also include basic cations and organic cations;

[0030] The alkaline cation includes any one or more of potassium ions, sodium ions, and lithium ions, which undergo a polarization reaction with water molecules.

[0031] The organic cations, including any one or more of tetramethylammonium cations, tetraethylammonium cations, and choline ions, combine with carbon dioxide and amino acid anions to reduce the formation of oxidation products by the absorbent.

[0032] This invention also proposes a method for using a system for capturing and utilizing carbon dioxide from flue gas, comprising:

[0033] Based on the concentrations of amino acid anions, degradation products, peroxides, and metal cations in the reaction solvent of the absorbent detected by the absorption tower, and the reaction temperature, a set of state equations for the carbon dioxide capture of the absorbent is constructed as a state-space model of the reaction mechanism.

[0034] A solution state vector is constructed for the state space model of the reaction mechanism, which includes the reaction kinetic parameters of the absorbent to be estimated. The EKF algorithm is then used to solve the state space model of the reaction mechanism to determine the real-time evaluation values ​​of the reaction kinetic parameters of the absorbent to be estimated.

[0035] The loss assessment value of metal cations in the wastewater due to the degradation of the absorbent was calculated based on the real-time evaluation values, reaction temperature, flue gas oxygen concentration, and amino acid anion concentration.

[0036] Based on the assessment value of the loss of metal cations in the wastewater due to the degradation of the absorbent, the amount of metal cations added to the absorption tower is determined by a control model.

[0037] Furthermore, the process of constructing the equations of state for carbon dioxide capture by the absorbent includes:

[0038] An amino acid anion kinetic equation was constructed based on the amino acid anion concentration, the reaction kinetic parameters of the absorbent to be estimated, the reaction temperature, the inhibitory factor, and the amount of amino acid anion supplemented.

[0039] A degradation product kinetic equation was constructed based on the concentration of degradation products, the reaction kinetic parameters of the absorbent to be estimated, the reaction temperature, the concentration of superoxide radicals, the concentration of dissolved oxygen, and the inhibitory factor.

[0040] A superoxide radical kinetic equation was constructed based on superoxide radical concentration, superoxide radical generation rate constant, dissolved oxygen concentration, amino acid anion superoxide radical consumption rate constant, transition metal superoxide radical consumption rate constant, amino acid anion concentration, and transition metal ion concentration.

[0041] The inhibition factor is calculated based on the product of the catalytic decomposition constant and the concentration of metal cations, the product of the rate constant of transition metal consumption of superoxide radicals and the concentration of transition metal ions, the metal complexation shielding constant, and the product of the concentration of transition metal ions and the concentration of amino acid anions.

[0042] The carbon dioxide capture state equation set of the absorbent includes the amino acid anion kinetic equation, the degradation product kinetic equation, and the superoxide radical kinetic equation.

[0043] Furthermore, the process of solving the state-space model of the reaction mechanism using the EKF algorithm includes:

[0044] The concentrations of degradation products and amino acid anions were calculated using the carbon dioxide capture state equations of the absorbent.

[0045] The first state vector is constructed and the equation is solved by minimizing the squared difference between the concentration of the degradation products and the measured concentration of the degradation products.

[0046] Calculate the first rate of change and the second rate of change of the amino acid anion concentration, and construct a second state vector to solve the equation based on minimizing the ratio of the first rate of change and the second rate of change;

[0047] The reaction kinetic parameters of the absorbent to be estimated are solved by solving the equation using the first state vector, and the catalytic decomposition constant, the rate constant of transition metal consumption of superoxide radicals, and the metal complexation shielding constant are solved by solving the equation using the second state vector.

[0048] The state vector to be solved also includes the catalytic decomposition constant, the transition metal superoxide radical consumption rate constant, the metal complexation shielding constant, the metal cation concentration, the degradation product concentration, and the amino acid anion concentration.

[0049] Furthermore, the process of calculating the assessment value of the loss of metal cations in the wastewater due to the degradation of the absorbent includes:

[0050] The degradation rate of the metal cation absorbent was determined by substituting the real-time evaluation values, reaction temperature, flue gas oxygen concentration, amino acid salt concentration, and metal complex shielding efficiency into the soft measurement equation.

[0051] The assessment value of metal cation loss due to the degradation rate of the metal cation absorbent, the flow rate of the absorbent discharge, and the metal concentration in the discharge flow are used to determine the assessment value of the metal cation loss due to the degradation of the absorbent discharge.

[0052] Furthermore, the process of determining the amount of metal cations to be added includes:

[0053] The metal ion concentration error is passed through the PID-based control model to generate a feedback compensation term;

[0054] The sum of the feedback compensation item and the assessed value of the loss of metal cations due to the degradation of wastewater by the absorbent is taken as the amount of metal cations added.

[0055] Compared with the prior art, the beneficial effects of the present invention are that, through the dual synergistic protection of cations and transition metal complexes in the absorbent, both react directionally with the chain proliferation products, cutting off the oxidative degradation path from the middle of the reaction chain of amino acid anions. The reaction between the transition metal complexes and amino acid anions significantly improves the solubility of the absorbent in water, effectively avoiding the problem of amino acid salt crystallization under low temperature or high concentration conditions, ensuring uniform spray atomization in the absorption tower and sufficient desorption reaction in the regeneration tower, and greatly reducing the degradation products of the absorbent, thereby reducing wastewater treatment costs and environmental risks. It not only achieves the reduction of carbon dioxide emissions from flue gas, but also converts the captured carbon dioxide into high-purity resource products, realizing the synergistic effect of the various components of the absorbent and the efficient matching of carbon dioxide capture and utilization processes.

[0056] In particular, this invention employs an ionic absorbent design with a solute saturated vapor pressure approaching zero, significantly reducing absorbent volatilization losses. Through metal complexes with nonpolar and polar amino acid anions, the solubility and stability of amino acids in aqueous solutions are greatly enhanced, effectively accelerating carbon dioxide mass transfer and reaction rates. Simultaneously, crystallization under low-temperature or high-concentration conditions is avoided, ultimately achieving a breakthrough improvement in carbon dioxide capture efficiency, suitable for high-load industrial flue gas treatment requirements. Amino acid anions form a stable hydrogen bond network with water molecules through polar groups in their molecular structure. Combined with the synergistic effect of the ionic atmosphere of high-concentration ionic amino acid salts, this significantly reduces the free movement of water molecules and the volatilization rate. The metal complexes can precisely target key intermediates in the oxidation process of amino acid anions, generating structurally stable compounds through chemical reactions, fundamentally blocking the chain reaction pathway of oxidative degradation. The complexation and decomplexation reactions between the metal complexes and amino acid anions exhibit good reversibility, acting as a reaction heat buffer in carbon dioxide desorption and utilization, significantly reducing desorption energy consumption and significantly improving the overall energy efficiency and economic feasibility of the process.

[0057] In particular, based on key measured indicators such as amino acid anion concentration, degradation product concentration, and peroxide concentration within the absorption tower, this invention constructs a state-space model of the reaction mechanism, including kinetic equations for amino acid anions, degradation products, and superoxide radicals. This model comprehensively characterizes the coupled reaction mechanism of flue gas carbon dioxide capture and absorbent oxidative degradation, accurately quantifies the inhibitory effect of metal cations and transition metal complexes on the oxidation reaction, and achieves a precise and comprehensive description of the absorbent reaction system. By constructing a state vector to be solved, including reaction kinetic parameters, inhibition-related constants, and the concentration of each component, and utilizing the EKF algorithm combined with a dual-objective solution logic of minimizing the squared difference of degradation product concentrations and matching the rate of change of amino acid anion concentration, the invention achieves real-time and accurate identification of the kinetic parameters and key constants to be estimated, reduces evaluation errors, and ensures that the concentration of metal cations within the absorption tower remains stable within the optimal range. This avoids both insufficient antioxidant capacity due to insufficient dosage and resource waste and cost increases caused by excessive dosage, achieving efficient capture of carbon dioxide in flue gas, stable circulation of the absorbent, and resource recovery and utilization. Attached Figure Description

[0058] Figure 1 This is a schematic diagram of the structure of a flue gas carbon dioxide capture and utilization system according to an embodiment of the present invention;

[0059] Figure 2 This is a schematic flowchart of the flue gas carbon dioxide capture and utilization method according to an embodiment of the present invention;

[0060] Figure 3 This is a schematic diagram of the process for constructing the state-space model of the reaction mechanism of the flue gas carbon dioxide capture and utilization method according to an embodiment of the present invention.

[0061] Figure 4 This is a schematic flowchart illustrating the process of solving the absorbent reaction kinetic parameters in the flue gas carbon dioxide capture and utilization method according to an embodiment of the present invention. Detailed Implementation

[0062] To make the objectives and advantages of the present invention clearer, the present invention will be further described below with reference to embodiments; it should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0063] Preferred embodiments of the present invention will now be described with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of the present invention and are not intended to limit the scope of protection of the present invention.

[0064] It should be noted that in the description of this invention, the terms "upper", "lower", "left", "right", "inner", "outer", etc., which indicate directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. This is only for the convenience of description and is not intended to indicate or imply that the device or element must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this invention.

[0065] Furthermore, it should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0066] like Figures 1 to 4 As shown, the present invention provides a method and system for capturing and utilizing carbon dioxide in flue gas. Through an absorption tower, a regeneration tower and a multifunctional absorbent system, it achieves efficient capture of carbon dioxide in flue gas, stable circulation of the absorbent, and resource recovery and utilization.

[0067] like Figure 1 As shown in the figure, this embodiment proposes a system for capturing and utilizing carbon dioxide from flue gas. The system includes:

[0068] An absorption tower is filled with an absorbent and circulated with flue gas emitted from the factory to capture carbon dioxide from the flue gas.

[0069] The regeneration tower is used to pass in an absorbent that combines with carbon dioxide to recover the absorbent and produce pure carbon dioxide.

[0070] The absorbent comprises amino acid anions, cations, and transition metal complexes;

[0071] The amino acid anions are used to absorb carbon dioxide and react with superoxide radicals to carry out chain proliferation.

[0072] The cation reacts with the products of the chain proliferation to reduce the loss of the chain proliferation.

[0073] The transition metal complex reacts with the products of the chain proliferation to reduce the loss of the chain proliferation, and also reacts with the amino acid anion to improve the solubility of the absorbent.

[0074] Furthermore, the amino acid anion includes any one or more of nonpolar amino acid anions and polar amino acid anions, and the reaction process of the amino acid anion reacting with superoxide radicals to carry out chain proliferation is as follows: .

[0075] Specifically, the function of metal complexes is to increase the stability of the absorbent while reducing the energy consumption of carbon dioxide desorption. During the oxidative degradation of amino groups, free radicals such as oxygen generally attack the hydrogen atom on the first carbon atom bonded to the amino group (i.e., α-CH), whose low bond dissociation energy (BDE) makes it the primary site of oxidative attack. First, oxygen is activated to generate superoxide radicals (·O2⁻), followed by hydroxyl radicals or superoxide radicals R-CH(NH2)COO. − Attacks α-CH to form α-carbon radical RC⋅(NH₂)COO − Then, the α-carbon free radical combines with oxygen to generate superoxide free radical. The generated α-carbon peroxide free radical will continuously take away the α-hydrogen of other amino acids through chain reaction, attack undegraded amino acids, and trigger chain proliferation.

[0076] The amino acid anions described in this embodiment are one or more combinations of nonpolar amino acid anions or polar amino acid anions. The role of nonpolar amino acid anions is to improve the carbon dioxide absorption efficiency of the absorbent, while the role of polar amino acid anions is to increase the solubility of ionic absorbents in water and improve carbon dioxide capture performance. At the same time, another role of polar amino acid anions is to form complexes with transition metal cations, thereby increasing the solubility of metal ions in the absorbent.

[0077] Furthermore, the nonpolar amino acid anion includes any one or more of α-alanine anion, β-alanine anion, 2-aminoisobutyric acid anion, and proline anion;

[0078] The polar amino acid anion includes any one or more of glycine anion, arginine anion, sarcosine anion, taurine anion, glutamic acid anion, lysine anion, asparagine anion, and aspartic acid anion; the metal complex includes any one or more of chromium, manganese, nickel, copper, zinc, and cobalt that coordinate with the amino acid anion.

[0079] The third feature of this embodiment is the addition of a variable-valence transition metal complex. The addition of a reduced transition metal complex has the following first function: to improve the antioxidant stability of the absorbent. The mechanism of action is that the reduced metal complex reacts with the intermediate products amine radicals or imine radicals in the oxidation process of amino acid anions to generate compounds with stable structures, thereby blocking the reaction pathway of the amino acid anion oxidation process and significantly reducing the oxidative degradation of the absorbent. The second function is to act as a heat buffer medium to recover the reaction heat of the amino acid anion in the process of absorbing carbon dioxide, thereby reducing the desorption energy consumption. The third function is to undergo a complexation reaction with amino acid anions to increase the solubility of amino acid salts in water.

[0080] Furthermore, the cation includes a metal cation, and the metal cation includes Cr. 3+ Ni 2+ Al 3+ Mn 2+ Co 2+ Zn 2+ The reaction process in which any one or more of the metal cations react with the products of chain proliferation to reduce the loss of said chain proliferation is as follows:

[0081]

[0082] Where M represents Cr 3+ Ni 2+ Al 3+ Mn 2+ Co 2+ Zn 2+ Any one of them.

[0083] Specifically, this embodiment introduces metal cations such as Cr3+, Ni2+, Al3+, Mn2+, Co2+, and Zn2+ as antioxidants. These ions (represented by M) can combine with amino acid anions to varying degrees to form coordination complexes (octahedral or tetrahedral coordination, etc.) to fix reaction sites and thus shield active groups that are easily attacked by oxidation.

[0084] The calculation results, as shown in Example 7, indicate that the complexation shielding effect is more significant when the antioxidant concentration is about 5% of the amino acid salt concentration, and the main absorbent solution is about 2~3M. Considering the actual solubility of metal ions, this upper limit will be further reduced.

[0085] Furthermore, the cations also include basic cations and organic cations;

[0086] The alkaline cation includes any one or more of potassium ions, sodium ions, and lithium ions, which undergo a polarization reaction with water molecules.

[0087] The organic cations, including any one or more of tetramethylammonium cations, tetraethylammonium cations, and choline ions, combine with carbon dioxide and amino acid anions to reduce the formation of oxidation products by the absorbent.

[0088] Specifically, the cations include one or more of basic cations (potassium ions, sodium ions, lithium ions) and organic cations (tetramethylammonium cations, tetraethylammonium cations, choline ions). Basic cations have small ionic radii and extremely high charge densities, exhibiting strong polarization capabilities towards water molecules. They form a tight hydration shell containing multiple water molecules, which coordinate with the basic cations through the lone pair electrons of their oxygen atoms, forming a stable coordination structure that reduces the free movement of water molecules and significantly decreases water loss. Organic cations such as tetramethylammonium cations, tetraethylammonium cations, and choline ions possess amino groups, exhibiting strong binding affinity to carbon dioxide. They also form stable compounds with amino acid anions, effectively increasing the carbon dioxide absorption rate.

[0089] The amino acid anion is one or more of nonpolar amino acid anions or polar amino acid anions. Preferably, the nonpolar amino acid anion is one or more of α-alanine anion, β-alanine anion, 2-aminoisobutyric acid anion, and proline anion, and the polar amino acid anion is one or more of glycine anion, arginine anion, sarcosine anion, taurine anion, glutamic acid anion, lysine anion, asparagine anion, and aspartic acid anion.

[0090] Preferably, the molar concentration of the cation is 2 to 5 mol / L, the molar concentration of the amino acid anion is 2 to 5 mol / L, and the concentration of the metal complex is 0.05-0.5 mol / L.

[0091] The absence of volatilization loss of the absorbent is illustrated by the following comparative examples and embodiments:

[0092] Comparative Example 1: Carbon capture of 10% flue gas was performed using a 3M ethanolamine solution with an inlet flow rate of 1 L / min (10% CO2, 90% N2) mixed gas, achieving an absorption load of 0.45 mol / mol. Aspen Plus simulation results showed that approximately 1.2 kg of ethanolamine was lost through volatilization for every ton of CO2 captured at the absorption end. Desorption at 105 °C and 75 kPa resulted in a loss of 5.1 kg of ethanolamine per ton of CO2 desorbed at the desorption end.

[0093] Example 1: Carbon capture of 10% flue gas was performed using 100 ml of 3M potassium β-alanine. The inlet gas was a mixture of 10% CO2 and 90% N2 at a flow rate of 1 L / min, achieving an absorption load of 0.45 mol / mol. The amino acid salt content in the solution before and after the experiment was titrated, and the amino acid salt content was approximately 38.1 g in both cases. The evaporation rate at the absorption end was 0. Desorption was performed at 105 °C and 75 kPa. The amino acid salt content in the titrated distillate was 0, and the amino acid salt content in the remaining solution was still approximately 38 g, with a desorption evaporation rate of 0.

[0094] Comparing Example 1 and Comparative Example 1, the amino acid salt absorbent showed no loss of volatility, which significantly reduced carbon capture costs and extended carbon capture lifespan.

[0095] The significantly improved carbon capture efficiency of the absorbent is illustrated by the following comparative examples and embodiments:

[0096] Example 2: Carbon capture of 10% flue gas was performed using 100 ml of 3M potassium glycinate solution. The inlet gas was a mixture of 10% CO2 and 90% N2 at a flow rate of 1 L / min. The CO2 concentration in the outlet gas was recorded over time, and the CO2 content in the solution was measured by titration. After 0.5 h, the outlet gas concentration was 1.52%, and after 1 h, 1.5 h, and 2 h, it was 3.51%, 7.25%, and 7.50%, respectively. After 2 h of absorption, the carbon loading of the solution was 36.8 L / L, and the average CO2 absorption rate was approximately 1.6 mol CO2 / L / h.

[0097] Comparative Example 2: Carbon capture was performed on 10% flue gas using 100 ml of 3M potassium hydroxide solution, with an inlet gas flow rate of 1 L / min (10% CO2, 90% N2). The outlet gas concentrations after 0.5 h, 1 h, 1.5 h, and 2 h were 0.52%, 6.93%, 8.15%, and 8.55%, respectively. After 2 h, the carbon load was 45.9 L / L, and the average CO2 absorption rate was approximately 2.3 mol CO2 / L / h.

[0098] Example 3: Carbon capture was performed on 10% flue gas at a flow rate of 1 L / min using a mixed solution of 100 ml of 1.5 M glycine and 1.5 M tetraethylammonium hydroxide. The outgassing concentrations after 0.5 h, 1 h, 1.5 h, and 2 h were 0.15%, 8.65%, 8.95%, and 9.05%, respectively. After 2 h, the carbon load was 49.9 L / L, and the average CO2 absorption rate was approximately 2.5 mol CO2 / L / h.

[0099] Comparing Example 3 with Example 2 and Comparative Example 2, for high-concentration CO2 mixtures, ionic absorbents can improve CO2 absorption rate and saturation and circulation capacity.

[0100] The following comparative examples illustrate how the absorbent reduces water evaporation:

[0101] Comparative Example 3: Carbon capture was performed on humidified air at a flow rate of 500 L / h (CO2 concentration 440 ppm) using 100 ml of 2M potassium hydroxide solution. After 32 h, the solution load reached 23.52 L / L, and the total sample volume was 17.4 ml. After another 32 h, the total solution volume was 80.2 ml, with a water loss of 2.4 ml. The water loss rate was 25 tons of water lost for every ton of CO2 captured from the air.

[0102] Example 4: Carbon capture was performed on humidified air at a flow rate of 500 L / h using 100 ml of 2M potassium β-alanine. After 32 hours, the solution load reached 23.32 L / L, and the total volume measured was 17.4 ml. After another 32 hours, the total solution volume was 82.2 ml, with a water loss of 0.4 ml. The water loss rate was 4 tons of water lost for every ton of CO2 captured.

[0103] Comparative Example 4: Carbon capture was performed directly on air (CO2 concentration 440 ppm) at a flow rate of 500 L / h using 100 ml of 2 M β-alanine potassium solution. The solution loadings after 16 h, 32 h, and 48 h were 16.7 L / L, 18.6 L / L, and 22.1 L / L, respectively. The water loss rates were 28%, 60%, and 76%, respectively.

[0104] Example 5: Carbon capture was performed directly on air at a flow rate of 500 L / h using a mixed solution of 100 ml of 2M potassium β-alanine and 100 g / L lithium chloride. The solution loadings after 16 h, 32 h, and 48 h were 8.8 L / L, 19.6 L / L, and 21.1 L / L, respectively. The water loss rates were 18%, 41%, and 51%, respectively.

[0105] Example 6: Carbon capture was performed directly on air at a flow rate of 500 L / h using a mixed solution of 100 ml of 2M potassium β-alanine and 200 g / L lithium bromide. The solution loadings after 16 h, 32 h, and 48 h were 16.8 L / L, 20.1 L / L, and 20.6 L / L, respectively. The water loss rates were 22%, 32%, and 38%, respectively.

[0106] Comparing Example 5 with Example 4 and Comparative Example 3, the absorbent can not only significantly reduce water loss during carbon capture, but also improve the carbon capture rate.

[0107] The metal complex of the absorbent significantly improves antioxidant stability, as illustrated by the following comparative examples:

[0108] Amino acid ions containing carboxyl groups can bind to metal ions (such as Ni2+, Cr3+, etc.) through ionic bonds or as ligands. These metal ions can promote the formation of relatively stable intermediates during the oxidative degradation of organic amine absorbents through selective catalysis, thereby inhibiting the spread of free oxidation chain reactions and significantly improving the service life of absorbents.

[0109] Example 7: Using Ni 2+ For example, it can form a 1:1 ligand with NH3 to form a Ni[NH3] type complex with a reaction stability constant βn = 6.3 × 102, and the following reaction occurs:

[0110] Ni 2+ +RNH2→[Ni(RNH2)] 2+ ,

[0111] Because of their large stability constants, most metal ions are complexed. When the complexation shielding effect is significant, the concentration of free ligands should be equal to the concentration of free metal, at which point the critical point of complexation shielding is reached. The corresponding free metal concentration (denoted as [M]) required by chemical reaction equilibrium calculations satisfies: [M] 2 =C / βn

[0112] In the formula, M is the required free metal concentration, βn is the reaction stability constant, and C is the complex concentration, not exceeding 1. Calculations show that the suitable concentration of the required metal complex is approximately 4%. And Cd... 2+ Zn 2+ Co 2+ The calculated optimal concentrations for metal complexation are approximately 4.7%, 6.5%, and 8.8%.

[0113] According to Example 7, the highest concentration of antioxidants in the experiment did not exceed 10% of the concentration of added amino acid salts. Therefore, the experiment was carried out starting from 10%, and Example 8 was conducted. The results are shown below.

[0114] Example 8: Take 40 ml of 3M potassium β-alanine aqueous solution with a loading of 0.45 mol / mol, and add nickel sulfate at a ratio of 0.1 to prepare Ni 2+ The amino acid salt solution was placed in an oxidative degradation vessel, and oxygen was introduced at approximately 0.65 MPa. The temperature was raised to 110°C, and stirring was started. The pressure change inside the vessel over time was recorded. The time required for the pressure to decrease by 2 bar and 3 bar was 17.5 h and 29.5 h, respectively.

[0115] Example 9: 40 ml of a 3M potassium β-alanine aqueous solution with a loading of 0.45 mol / mol was added to zinc sulfate at a ratio of 0.1 to prepare a Zn2+-amino acid salt solution. This solution was placed in an oxidative degradation reactor, and oxygen was introduced at approximately 0.65 MPa. The temperature was raised to 110°C, and stirring was started. The time required for the pressure to decrease by 1 bar, 2 bar, and 3 bar was 8 h, 17 h, and 26 h, respectively.

[0116] Comparative Example 5: 40 ml of 3M potassium β-alanine aqueous solution was placed in an oxidative degradation vessel, oxygen was introduced at approximately 0.65 MPa, the temperature was raised to 110 °C, and stirring was started. The time required for the pressure to decrease by 1 bar, 2 bar, and 3 bar was 8.5 h, 12 h, and 20 h, respectively.

[0117] Comparing Examples 8 and 9 with Comparative Example 5, the rate of oxygen consumption during oxidative degradation was significantly reduced. This means that a 5% concentration of antioxidant can significantly reduce the rate of oxidative degradation and greatly improve oxidative stability. Next, the effects of ultra-low concentration antioxidants will be compared.

[0118] Example 10: Take 40 ml of 3M potassium β-alanine aqueous solution loaded with 0.45 mol / mol, and add manganese sulfate at a concentration of 1 mM to prepare Mn 2+ The amino acid salt solution was placed in an oxidative degradation vessel, and oxygen was introduced at approximately 0.65 MPa. The temperature was raised to 110°C, and stirring was started. The time required for the pressure to decrease by 1 bar, 2 bar, and 3 bar was 29 h, 43 h, and 54.5 h, respectively.

[0119] Example 11: Take 40 ml of 3M potassium β-alanine aqueous solution loaded with 0.45 mol / mol, and add cobalt sulfate at a concentration of 1 mM to prepare Co 2+ The amino acid salt solution was placed in an oxidative degradation vessel, and oxygen was introduced at approximately 0.65 MPa. The temperature was raised to 110°C, and stirring was started. The time required for the pressure to decrease by 1 bar, 2 bar, and 3 bar was 21 h, 32 h, and 41.5 h, respectively.

[0120] Comparative Example 6: 40 ml of 3M ethanolamine aqueous solution with a loading of 0.45 was placed in an oxidative degradation vessel, and oxygen was introduced at approximately 0.65 MPa. The temperature was raised to 110°C, and stirring was started. The time required for the pressure to decrease by 1 bar, 2 bar, and 3 bar was 13.5 h, 29.5 h, and 48 h, respectively.

[0121] Comparing Examples 11 and 10 with Comparative Example 6, the oxidative degradation rate of the ionic liquid absorbent after the addition of antioxidants was significantly reduced, and its oxidative stability was significantly higher than that of existing organic amine systems such as ethanolamine.

[0122] In practical industrial applications, trace amounts (on the order of milliseconds) of the metallic components in the stainless steel will dissolve in the absorbent. For example, Fe... 3+ Cr 3+ Ni 2+ These factors may affect the oxidative degradation rate, as investigated through the following implementation case:

[0123] Example 12: Take 40 ml of 3M glycine tetramethylammonium hydroxide aqueous solution with a loading of 0.45, and add ferric sulfate, nickel, chromium and manganese sequentially in a concentration ratio of 1 mM: 0.1 mM: 0.1 mM: 0.1 mM to prepare Mn + The ionic liquid mixture was placed in an oxidative degradation vessel, and oxygen at approximately 0.65 MPa was introduced. The temperature was raised to 110°C, and stirring was started. The time required for the pressure to decrease by 1 bar, 2 bar, and 3 bar was 34 h, 50 h, and 63 h, respectively.

[0124] Comparative Example 7: Take 40 ml of a 3M aqueous solution of glycine tetramethylammonium hydroxide with a loading of 0.45, and add ferric sulfate at a concentration of 1 mM to prepare Fe... 3+- The ionic liquid is placed in an oxidative degradation vessel, oxygen is introduced at approximately 0.65 MPa, the temperature is raised to 110°C, and stirring is started. The time required for the pressure to decrease by 1 bar, 2 bar, and 3 bar is 3.5 h, 8 h, and 13.5 h, respectively.

[0125] Comparing Example 12 with Comparative Examples 6 and 7, the oxidative stability of the ionic liquid absorbent invented in this study is significantly higher than that of existing organic amine systems such as ethanolamine, and its service life is expected to be extended by more than 60%.

[0126] The significant reduction in desorption energy consumption of the absorbent is illustrated by the following comparative examples:

[0127] Comparative Example 8: Using 100 ml of 3M ethanolamine solution, the loading reached 33.5 L / L. Rotary evaporation was performed at 105 °C and 76 kPa for 1.5 h, and the changes in solution volume and CO2 content before and after desorption were measured. The desorption rate was 65.5%, and the desorption energy consumption was 5.4 GJ / ton CO2.

[0128] Example 13: A Ni2+-amino acid salt solution was prepared by adding nickel sulfate at a concentration of 1 mM to 100 ml of a 1:1 mixture of 3M potassium β-alanine and potassium glutamate, achieving a loading of 32.9 L / L. The solution was rotary evaporated at 105 °C and 76 kPa for 1.5 h, and the changes in solution volume and CO2 content before and after desorption were measured. The desorption rate was 64.7%, and the desorption energy consumption was 4.3 GJ / ton CO2.

[0129] Compared with Comparative Example 8, Example 13 shows that the desorption energy consumption of the ionic liquid absorbent invented in this study is reduced by more than 20%.

[0130] In summary, this embodiment solves the problems of high volatility, low carbon capture rate, large moisture loss, and high desorption energy consumption of traditional carbon capture absorbents.

[0131] like Figure 2 As shown in the figure, this embodiment also provides a method for capturing and utilizing carbon dioxide in flue gas, the method comprising:

[0132] Based on the concentrations of amino acid anions, degradation products, peroxides, and metal cations in the reaction solvent of the absorbent detected by the absorption tower, and the reaction temperature, a set of state equations for the carbon dioxide capture of the absorbent is constructed as a state-space model of the reaction mechanism.

[0133] A solution state vector is constructed for the state space model of the reaction mechanism, which includes the reaction kinetic parameters of the absorbent to be estimated. The EKF algorithm is then used to solve the state space model of the reaction mechanism to determine the real-time evaluation values ​​of the reaction kinetic parameters of the absorbent to be estimated.

[0134] The loss assessment value of metal cations in the wastewater due to the degradation of the absorbent was calculated based on the real-time evaluation values, reaction temperature, flue gas oxygen concentration, and amino acid anion concentration.

[0135] Based on the assessment value of the loss of metal cations in the wastewater due to the degradation of the absorbent, the amount of metal cations added to the absorption tower is determined by a control model.

[0136] like Figure 3 As shown, the process of constructing the carbon dioxide capture equations for the absorbent further includes:

[0137] An amino acid anion kinetic equation was constructed based on the amino acid anion concentration, the reaction kinetic parameters of the absorbent to be estimated, the reaction temperature, the inhibitory factor, and the amount of amino acid anion supplemented.

[0138] A degradation product kinetic equation was constructed based on the concentration of degradation products, the reaction kinetic parameters of the absorbent to be estimated, the reaction temperature, the concentration of superoxide radicals, the concentration of dissolved oxygen, and the inhibitory factor.

[0139] A superoxide radical kinetic equation was constructed based on superoxide radical concentration, superoxide radical generation rate constant, dissolved oxygen concentration, amino acid anion superoxide radical consumption rate constant, transition metal superoxide radical consumption rate constant, amino acid anion concentration, and transition metal ion concentration.

[0140] The inhibition factor is calculated based on the product of the catalytic decomposition constant and the concentration of metal cations, the product of the rate constant of transition metal consumption of superoxide radicals and the concentration of transition metal ions, the metal complexation shielding constant, and the product of the concentration of transition metal ions and the concentration of amino acid anions.

[0141] The carbon dioxide capture state equation set of the absorbent includes the amino acid anion kinetic equation, the degradation product kinetic equation, and the superoxide radical kinetic equation.

[0142] Specifically, the amino acid anion kinetic equation, degradation product kinetic equation, superoxide radical kinetic equation, and inhibitory factor are, in order:

[0143] ;

[0144] In the formula, The concentrations of amino acid anions at time k+1, amino acid anions at time k, degradation products at time k+1, degradation products at time k, superoxide radicals at time k+1, superoxide radicals at time k, and dissolved oxygen at time k (directly measured by the online dissolved oxygen sensor of the absorption tower) represent the concentrations of amino acid anions at time k+1, degradation products at time k, superoxide radicals at time k, and dissolved oxygen at time k, respectively. Indicates the discrete time step. These are all parameters of the absorbent reaction kinetics to be estimated. Denotes the apparent degradation rate constant at time k. This represents the apparent activation energy at time k. This represents the universal gas constant, which is 8.314. This represents the reaction temperature at time k (measured directly by the temperature sensor in the absorption tower). Denotes the inhibition factor at time k. For the error term, These represent the superoxide radical generation rate constant (preferably 0.01 to 0.05, determined through laboratory calibration). The rate constant of amino acid anion consumption of superoxide radicals (preferably 1 to 3, determined by laboratory calibration). The rate constant for the consumption of superoxide radicals by transition metals (preferably 0.5 to 2.0, determined through laboratory calibration). This represents the concentration of transition metal ions at time k. These represent the catalytic decomposition constant, the transition metal superoxide radical consumption rate constant, and the metal complexation shielding constant, respectively. This indicates the concentration of metal cations.

[0145] like Figure 4 As shown, the process of solving the state-space model of the reaction mechanism using the EKF algorithm further includes:

[0146] The concentrations of degradation products and amino acid anions were calculated using the carbon dioxide capture state equations of the absorbent.

[0147] The first state vector is constructed and the equation is solved by minimizing the squared difference between the concentration of the degradation products and the measured concentration of the degradation products.

[0148] Calculate the first rate of change and the second rate of change of the amino acid anion concentration, and construct a second state vector to solve the equation based on minimizing the ratio of the first rate of change and the second rate of change;

[0149] The reaction kinetic parameters of the absorbent to be estimated are solved by solving the equation using the first state vector, and the catalytic decomposition constant, the rate constant of transition metal consumption of superoxide radicals, and the metal complexation shielding constant are solved by solving the equation using the second state vector.

[0150] The state vector to be solved also includes the catalytic decomposition constant, the transition metal superoxide radical consumption rate constant, the metal complexation shielding constant, the metal cation concentration, the degradation product concentration, and the amino acid anion concentration.

[0151] Specifically, the solution process for the state-space model of the reaction mechanism is based on the standard EKF algorithm, with the addition of mechanistic constraints: ;

[0152] In the formula, Denotes the inhibition factor at time k. Denotes the apparent degradation rate constant at time k. This represents the apparent activation energy at time k. These represent the catalytic decomposition constant, the transition metal superoxide radical consumption rate constant, and the metal complexation shielding constant, respectively.

[0153] Specifically, the equations for solving the first state vector and the equations for solving the second state vector are as follows: ;

[0154] In the formula, These include the reaction kinetic parameters of the absorbent to be estimated. The first solution variables include the catalytic decomposition constant, the transition metal superoxide radical consumption rate constant, and the metal complexation shielding constant. The second solution variable, This represents the solution calculation of the EKF algorithm. Representing the measured concentration of degradation products, respectively, and the state vector obtained by substituting the degradation product kinetic equation into the solution. The concentration of degradation products at time k+1 was calculated. Denotes the apparent degradation rate constant at time k. This represents the apparent activation energy at time k. These represent the first rate of change and the second rate of change of the amino acid anion concentration, respectively (both are variable rates within a discrete time step). These represent the catalytic decomposition constant, the transition metal superoxide radical consumption rate constant, and the metal complexation shielding constant, respectively.

[0155] Therefore, the inhibitory effects of cations and transition metal complexes can be considered based on real-time measurement data from the absorption tower, allowing for the accurate calculation of the apparent degradation rate constant and apparent activation energy.

[0156] Furthermore, the process of calculating the assessment value of the loss of metal cations in the wastewater due to the degradation of the absorbent includes:

[0157] The degradation rate of the metal cation absorbent was determined by substituting the real-time evaluation values, reaction temperature, flue gas oxygen concentration, amino acid salt concentration, and metal complex shielding efficiency into the soft measurement equation.

[0158] The assessment value of metal cation loss due to the degradation rate of the metal cation absorbent, the flow rate of the absorbent discharge, and the metal concentration in the discharge flow are used to determine the assessment value of the metal cation loss due to the degradation of the absorbent discharge.

[0159] Specifically, the soft measurement equation and weighted calculation are as follows: ;

[0160] In the formula, This represents the degradation rate of the metal cation absorbent at time t. and These are all parameters of the absorbent reaction kinetics to be estimated. Represents the apparent degradation rate constant. Indicates the apparent activation energy. This represents the universal gas constant, which is 8.314. This represents the reaction temperature at time k (measured directly by the temperature sensor in the absorption tower). These represent the oxygen concentration and amino acid salt concentration in the flue gas, respectively. The shielding efficiency of the metal complex is indicated by an experimental value, preferably 0.3. This represents the assessed value of metal cation loss due to absorbent degradation at time t. , These represent the sludge flow rate and the metal concentration in the sludge flow rate of the absorption tower, respectively. , are weighting coefficients, preferably 0.8 and 0.2.

[0161] Furthermore, the process of determining the amount of metal cations to be added includes:

[0162] The metal ion concentration error is passed through the PID-based control model to generate a feedback compensation term;

[0163] The sum of the feedback compensation item and the assessed value of the loss of metal cations due to the degradation of wastewater by the absorbent is taken as the amount of metal cations added.

[0164] Specifically, the process for calculating the amount of metal cations added is as follows: ;

[0165] In the formula, This represents the amount of metal cations released at time t. This indicates the error in metal ion concentration. This represents the PID gain coefficient. This represents the assessed value of the loss of metal cations in the wastewater due to the degradation of the absorbent at time t.

[0166] Therefore, the above process can maintain the chemical stability and absorption capacity of the absorbent in the absorption tower.

[0167] In this embodiment, through the dual synergistic protection of cations and transition metal complexes in the absorbent, both react directionally with the chain proliferation products, interrupting the oxidative degradation pathway at the middle of the amino acid anion reaction chain. The reaction between the transition metal complexes and amino acid anions significantly improves the absorbent's solubility in water, effectively avoiding the problem of amino acid salt crystallization under low temperature or high concentration conditions. This ensures uniform spray atomization in the absorption tower and sufficient desorption reaction in the regeneration tower, resulting in a significant reduction in absorbent degradation products. This lowers wastewater treatment costs and environmental risks, not only reducing flue gas carbon dioxide emissions but also converting captured carbon dioxide into high-purity resource products, achieving a highly efficient match between the synergistic effects of the absorbent components and the carbon dioxide capture and utilization process. The ionic absorbent design results in a solute saturated vapor pressure close to zero, significantly reducing absorbent volatilization losses. By using metal complexes with nonpolar and polar amino acid anions, the solubility and stability of amino acids in aqueous solutions are significantly improved, effectively accelerating carbon dioxide mass transfer and reaction rates. Simultaneously, crystallization under low-temperature or high-concentration conditions is avoided, ultimately achieving a breakthrough in carbon dioxide capture efficiency, suitable for high-load industrial flue gas treatment requirements. Amino acid anions form a stable hydrogen bond network with water molecules through polar groups in their molecular structure. Combined with the synergistic effect of the ionic atmosphere of high-concentration ionic amino acid salts, this significantly reduces the free movement and volatilization rate of water molecules. Metal complexes can precisely target key intermediates in the oxidation process of amino acid anions, generating structurally stable compounds through chemical reactions, fundamentally blocking the chain reaction pathway of oxidative degradation. The complexation and decomplexation reactions between metal complexes and amino acid anions exhibit good reversibility, acting as a reaction heat buffer in carbon dioxide desorption and utilization, significantly reducing desorption energy consumption and significantly improving the overall energy efficiency and economic feasibility of the process. Based on key measured indicators such as amino acid anion concentration, degradation product concentration, and peroxide concentration within the absorber tower, a state-space model of the reaction mechanism is constructed, including kinetic equations for amino acid anions, degradation products, and superoxide radicals. This model comprehensively characterizes the coupled reaction mechanism of flue gas carbon dioxide capture and absorbent oxidative degradation, accurately quantifying the inhibitory effects of metal cations and transition metal complexes on the oxidation reaction, thus achieving a precise and comprehensive description of the absorbent reaction system. By constructing a state vector to be solved, including reaction kinetic parameters, inhibition-related constants, and the concentrations of each component, and utilizing the EKF algorithm combined with a dual-objective solution logic of minimizing the squared difference of degradation product concentrations and matching the rate of change of amino acid anion concentration, real-time and accurate identification of the kinetic parameters and key constants to be estimated is achieved. This reduces evaluation errors and ensures that the concentration of metal cations within the absorber tower remains stable within the optimal range. This avoids both insufficient antioxidant capacity due to under-dosing and resource waste and cost increases caused by over-dosing, achieving efficient carbon dioxide capture from flue gas, stable absorbent circulation, and resource recovery and utilization.

[0168] Those skilled in the art will recognize that the modules and algorithm steps of the examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0169] The technical solution of the present invention has been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of the present invention is obviously not limited to these specific embodiments. Without departing from the principles of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of the present invention.

[0170] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A system for capturing and utilizing carbon dioxide from flue gas, characterized in that, include: An absorption tower is filled with an absorbent and circulated with flue gas emitted from the factory to capture carbon dioxide from the flue gas. The regeneration tower is used to pass in an absorbent that combines with carbon dioxide to recover the absorbent and produce pure carbon dioxide. The absorbent comprises amino acid anions, cations, and transition metal complexes; The amino acid anions are used to absorb carbon dioxide and react with superoxide radicals to carry out chain proliferation. The cation reacts with the products of the chain proliferation to reduce the loss of the chain proliferation. The transition metal complex reacts with the products of the chain proliferation to reduce the loss of the chain proliferation, and also reacts with the amino acid anion to improve the solubility of the absorbent. The amino acid anions include any one or more of nonpolar amino acid anions and polar amino acid anions; The nonpolar amino acid anions include any one or more of α-alanine anion, β-alanine anion, 2-aminoisobutyric acid anion, and proline anion; The polar amino acid anions include any one or more of glycine anion, arginine anion, sarcosine anion, taurine anion, glutamic acid anion, lysine anion, asparagine anion, and aspartic acid anion; The transition metal complex includes products formed by coordination of any one or more of chromium, manganese, nickel, zinc, and cobalt with the amino acid anion.

2. The flue gas carbon dioxide capture and utilization system according to claim 1, characterized in that, The reaction process of amino acid anions reacting with superoxide radicals to carry out chain proliferation is as follows:

3. The flue gas carbon dioxide capture and utilization system according to claim 1, characterized in that, The cation includes a transition metal cation, which includes Cr. 3+ Ni 2+ Mn 2+ Co 2+ Zn 2+ The reaction process in which any one or more of the transition metal cations react with the products of chain proliferation to reduce the loss of said chain proliferation is as follows: M 2+ +2RNH2→[M(RNH2)2] 2+ , ， Where M represents Cr 3+ Ni 2+ Mn 2+ Co 2+ Zn 2+ Any one of them.

4. The flue gas carbon dioxide capture and utilization system according to claim 3, characterized in that, The cations also include basic metal cations and organic cations; The alkaline metal cations include any one or more of potassium ions, sodium ions, and lithium ions, which undergo polarization reactions with water molecules. The organic cations, including any one or more of tetramethylammonium cations, tetraethylammonium cations, and choline ions, combine with carbon dioxide and amino acid anions to reduce the formation of oxidation products by the absorbent.

5. A method for using a flue gas carbon dioxide capture and utilization system as described in any one of claims 1 to 4, comprising: Based on the concentrations of amino acid anions, degradation products, peroxides, transition metal cations, and reaction temperature in the reaction solvent of the absorbent detected by the absorption tower, a set of state equations for the carbon dioxide capture of the absorbent is constructed into a state-space model of the reaction mechanism. A solution state vector is constructed for the state space model of the reaction mechanism, which includes the reaction kinetic parameters of the absorbent to be estimated. The EKF algorithm is then used to solve the state space model of the reaction mechanism to determine the real-time evaluation values ​​of the reaction kinetic parameters of the absorbent to be estimated. The loss assessment value of transition metal cations in the degradation of wastewater by the absorbent is calculated based on the real-time evaluation values, reaction temperature, flue gas oxygen concentration, and amino acid anion concentration. Based on the assessment value of the loss of transition metal cations in the wastewater due to the degradation of the absorbent, the amount of transition metal cations added to the absorption tower is determined by a control model.

6. The method for capturing and utilizing carbon dioxide from flue gas according to claim 5, characterized in that, The process of constructing the equations of state for carbon dioxide capture by the absorbent includes: An amino acid anion kinetic equation was constructed based on the amino acid anion concentration, the reaction kinetic parameters of the absorbent to be estimated, the reaction temperature, the inhibitory factor, and the amount of amino acid anion supplemented. A degradation product kinetic equation was constructed based on the concentration of degradation products, the reaction kinetic parameters of the absorbent to be estimated, the reaction temperature, the concentration of superoxide radicals, the concentration of dissolved oxygen, and the inhibitory factor. A superoxide radical kinetic equation was constructed based on superoxide radical concentration, superoxide radical generation rate constant, dissolved oxygen concentration, amino acid anion superoxide radical consumption rate constant, transition metal superoxide radical consumption rate constant, amino acid anion concentration, and transition metal cation concentration. The inhibition factor is calculated based on the product of the catalytic decomposition constant and the transition metal cation concentration, the product of the transition metal superoxide radical consumption rate constant and the transition metal cation concentration, the metal complexation shielding constant, and the product of the transition metal cation concentration and the amino acid anion concentration. The carbon dioxide capture state equation set of the absorbent includes the amino acid anion kinetic equation, the degradation product kinetic equation, and the superoxide radical kinetic equation.

7. The method for capturing and utilizing carbon dioxide from flue gas according to claim 6, characterized in that, The process of solving the state-space model of the reaction mechanism using the EKF algorithm includes: The concentrations of degradation products and amino acid anions were calculated using the carbon dioxide capture state equations of the absorbent. The first state vector is constructed and the equation is solved by minimizing the squared difference between the concentration of the degradation products and the measured concentration of the degradation products. Calculate the first rate of change and the second rate of change of the amino acid anion concentration, and construct a second state vector to solve the equation based on minimizing the ratio of the first rate of change and the second rate of change; The reaction kinetic parameters of the absorbent to be estimated are solved by solving the equation using the first state vector, and the catalytic decomposition constant, the rate constant of transition metal consumption of superoxide radicals, and the metal complexation shielding constant are solved by solving the equation using the second state vector. The state vector to be solved also includes the catalytic decomposition constant, the transition metal superoxide radical consumption rate constant, the metal complexation shielding constant, the transition metal cation concentration, the degradation product concentration, and the amino acid anion concentration.

8. The method for capturing and utilizing carbon dioxide from flue gas according to claim 5, characterized in that, The process of calculating the assessment value of the loss of transition metal cations in wastewater due to the degradation of absorbents includes: Substituting the real-time evaluation values, reaction temperature, flue gas oxygen concentration, amino acid salt concentration, and transition metal complex shielding efficiency into the soft measurement equation, the degradation rate of the transition metal cation absorbent was determined. The assessment value of the loss of transition metal cations in the wastewater discharge is determined by a weighted calculation based on the degradation rate of the transition metal cation absorbent, the wastewater discharge flow rate of the absorption tower, and the metal concentration in the wastewater discharge flow.

9. The method for capturing and utilizing carbon dioxide in flue gas according to claim 5, characterized in that, The process of determining the amount of transition metal cations to be added includes: The transition metal cation concentration error is passed through the PID-based control model to generate a feedback compensation term; The sum of the feedback compensation item and the assessment value of the loss of transition metal cations due to the degradation of wastewater by the absorbent is taken as the amount of transition metal cations added.

Images